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15.8 Less aggressive aortic valve replacement—the ministernotomy approach
Cardiac Valves I can suddenly enlarge to cause catastrophic failure. The lateral edges of the leaflets are designed with a clearance between the internal surface of the annulus. This provides a controlled forward and backward flow that washes the hinges throughout the cardiac cycle. Postoperative results for up to 2% years in over 900 patients (over 1,200 “patient-years”) including both mitral and aortic valves and those who did not follow an anti-coagulation regimen have shown an incidence of thrombosis of less than 0.5 per 100 patient-years and a TE incidence of less than 1.0 per 100 patient-years. There have been no significant incidents of hemolysis or perivalvular leak and no instances of functional or mechanical failure.
15.8 Less Aggressive Aortic Valve Replacement-the M inisternotomy Approach l? BERGMANN, H. MACHLER, D. DACAR, 1. KNEZ, I. SCHAFHALTER, M . ANECLI-MONTI and B. RIGLER, Graz, Austria
15.7 Aortic Valve Replacement in Small Aortic Annulus: Which Type of Prosthesis Should be Denied? An “in vitro-in vivo” Evaluation G. GEROSA, R. BIANCO, L. TESTOLIN, C. MUNERETTO and D. CASAROTTO, Padova, Italy The aim of this study was to investigate the in vitro and in viva haemodynamic performances of currently available valve substitutes including: (1) bileaflet mechanical prosthesis (St. Jude-EC); (2) modified bileaflet mechanical prosthesis (St. Jude-HP); (3) modified stented bioprosthesis (St. Jude X-Cell); (4) subcoronary stentless (Toronto SW); (5) miniroot stentless (Medtronic Freestyle). For “in vitro” evaluation the different devices were implanted in a 21 m m artificial aortic root. The size of each device was chosen in order to fit properly and ranged from 21 m m (mechanical valves and stented bioprostheses) to 23 m m (stentless bioprostheses). “In vitro” assessment was carried out in a specially designed pulse duplicator. “In viva” evaluation included 40 patients who received a 21 m m aortic valve prosthesis: St. Jude-EC, St.JudeHP and St. Jude X-Cell. Haemodynamic evaluation was carried out 6 months postoperatively by means of 2D Color Doppler Echocardiography. The mean aortic pressure, heart rate, stroke volume and CO of each patient were reproduced in the pulse duplicator in order to assess the reliability of in vitro testing. The tables below summarize the “in vitro” and “in viva” haemodynamic performance of each prosthesis.
co i’lfm’)
Mean gradient
WV
4.5
Freestyle
4.5
S.J.-HP S.J.-EC: S.J.-XCZell
4.7 f 1.5 4.5 f 1.4 4.5 + 1.2
8.1 11.2 12.7 16.1 21.8
Type o/ prostbesrs
t 2 2 2 2
Peak gradient 1.3 1.2 3.9 5.1 2.2
20.6 25.8 22.3 29.8 35.6
k t + z 2
3.5 2.8 4.8 5.2 4.5
“In rho” results
CO S.J:HI’ S.J.-EC: S.J.-X(:ell
,1/W?‘)
Mean gradient
Peak gradient
4.: f 1.5 4.5 + 1.4 4.5 2 1.2
12.2 * 3.1 15.4 i 6.2 22.0 + 2.2
22.1 * 3.9 28.9 + 7.4 36.5 f 5.6
CARDIOVASCULAR SURGERY SEPTEMBER 1997
Direct comparison of “in vitro” and “in &o” results showed a striking correspondence. This fact could be of paramount value in preimplant evaluation and selection of prostheses for an optimal patient/device match. According to our data in the presence of a small aortic annulus prosthesis selection should be confined to stentless bioprosthesis (s&coronary) and modified bileaflet mechanical valve. In the presence of an aortic annulus smaller than 21 m m annulus enlargement or total root replacement should be considered the procedure of choice.
Introduction: Conventional aortic valve replacement (AVR) is a safe and effective procedure with low morbidity and mortality. However, cardiac surgery trends to minimize invasive procedures in order to reduce rhe patients’ postoperative discomfort and to increase the postoperative mobilization. Methods and results: Between July and December 1996 a total of 22 elective and consecutive patients requiring valvular heart surgery were operated upon a minimal access protocol. A midline skin incision (8-12cm in length) was performed from the first to the third or fourth interspace. Cannulation of the ascending aorta was performed as usual. The venous canula was inserted subyxphoidally and intrapericardially. Surgery on the aortic was performed with exellent exposure. After weaning from bypass and decannulation, the drainage tube was introduced through the wound of the venous cannula. Comparing the conventional AVR versus the less aggressive method there were no differences in the mean aortic cross clamping period (82min (38-95) versus 79min (41-91)) or in the operation duration (198 min (145-445) versus 192 m m (1.58-466)). Patients were extubated earlier in the ministernotomy group (mean 9 h (4.2-20.5) versus mean 11.2 h (6.5-23 hi. There was the trend to less analgetica consumption, less postoperative drainage bleeding and the trend to a shorter period of mobilization. The patients were very satisfied with the cosmetic result. During surgery, conversion to the standard technique was not required in any patient. ‘The replacement with stentless xenografts could be performed without undue extension of either cross clamp or cardiopulmonary bypass time. No procedure related mortality occurred. Posroperatively there was one case of a prosthetic leakage requiring a redo-AVR 2 month postoperatively. The USC of the partial sternotomy minimizes the incision wound size and reduces postoperative pain. Conclusion: Our experiences indicate this mrnisternotomy approach as a very suitable and safe alternative to elective AVR with both mechanical as well as stemless protheses.
77
15.8 Less Aggressive Aortic Valve Replacement-the M inisternotomy Approach l? BERGMANN, H. MACHLER, D. DACAR, 1. KNEZ, I. SCHAFHALTER, M . ANECLI-MONTI and B. RIGLER, Graz, Austria
15.7 Aortic Valve Replacement in Small Aortic Annulus: Which Type of Prosthesis Should be Denied? An “in vitro-in vivo” Evaluation G. GEROSA, R. BIANCO, L. TESTOLIN, C. MUNERETTO and D. CASAROTTO, Padova, Italy The aim of this study was to investigate the in vitro and in viva haemodynamic performances of currently available valve substitutes including: (1) bileaflet mechanical prosthesis (St. Jude-EC); (2) modified bileaflet mechanical prosthesis (St. Jude-HP); (3) modified stented bioprosthesis (St. Jude X-Cell); (4) subcoronary stentless (Toronto SW); (5) miniroot stentless (Medtronic Freestyle). For “in vitro” evaluation the different devices were implanted in a 21 m m artificial aortic root. The size of each device was chosen in order to fit properly and ranged from 21 m m (mechanical valves and stented bioprostheses) to 23 m m (stentless bioprostheses). “In vitro” assessment was carried out in a specially designed pulse duplicator. “In viva” evaluation included 40 patients who received a 21 m m aortic valve prosthesis: St. Jude-EC, St.JudeHP and St. Jude X-Cell. Haemodynamic evaluation was carried out 6 months postoperatively by means of 2D Color Doppler Echocardiography. The mean aortic pressure, heart rate, stroke volume and CO of each patient were reproduced in the pulse duplicator in order to assess the reliability of in vitro testing. The tables below summarize the “in vitro” and “in viva” haemodynamic performance of each prosthesis.
co i’lfm’)
Mean gradient
WV
4.5
Freestyle
4.5
S.J.-HP S.J.-EC: S.J.-XCZell
4.7 f 1.5 4.5 f 1.4 4.5 + 1.2
8.1 11.2 12.7 16.1 21.8
Type o/ prostbesrs
t 2 2 2 2
Peak gradient 1.3 1.2 3.9 5.1 2.2
20.6 25.8 22.3 29.8 35.6
k t + z 2
3.5 2.8 4.8 5.2 4.5
“In rho” results
CO S.J:HI’ S.J.-EC: S.J.-X(:ell
,1/W?‘)
Mean gradient
Peak gradient
4.: f 1.5 4.5 + 1.4 4.5 2 1.2
12.2 * 3.1 15.4 i 6.2 22.0 + 2.2
22.1 * 3.9 28.9 + 7.4 36.5 f 5.6
CARDIOVASCULAR SURGERY SEPTEMBER 1997
Direct comparison of “in vitro” and “in &o” results showed a striking correspondence. This fact could be of paramount value in preimplant evaluation and selection of prostheses for an optimal patient/device match. According to our data in the presence of a small aortic annulus prosthesis selection should be confined to stentless bioprosthesis (s&coronary) and modified bileaflet mechanical valve. In the presence of an aortic annulus smaller than 21 m m annulus enlargement or total root replacement should be considered the procedure of choice.
Introduction: Conventional aortic valve replacement (AVR) is a safe and effective procedure with low morbidity and mortality. However, cardiac surgery trends to minimize invasive procedures in order to reduce rhe patients’ postoperative discomfort and to increase the postoperative mobilization. Methods and results: Between July and December 1996 a total of 22 elective and consecutive patients requiring valvular heart surgery were operated upon a minimal access protocol. A midline skin incision (8-12cm in length) was performed from the first to the third or fourth interspace. Cannulation of the ascending aorta was performed as usual. The venous canula was inserted subyxphoidally and intrapericardially. Surgery on the aortic was performed with exellent exposure. After weaning from bypass and decannulation, the drainage tube was introduced through the wound of the venous cannula. Comparing the conventional AVR versus the less aggressive method there were no differences in the mean aortic cross clamping period (82min (38-95) versus 79min (41-91)) or in the operation duration (198 min (145-445) versus 192 m m (1.58-466)). Patients were extubated earlier in the ministernotomy group (mean 9 h (4.2-20.5) versus mean 11.2 h (6.5-23 hi. There was the trend to less analgetica consumption, less postoperative drainage bleeding and the trend to a shorter period of mobilization. The patients were very satisfied with the cosmetic result. During surgery, conversion to the standard technique was not required in any patient. ‘The replacement with stentless xenografts could be performed without undue extension of either cross clamp or cardiopulmonary bypass time. No procedure related mortality occurred. Posroperatively there was one case of a prosthetic leakage requiring a redo-AVR 2 month postoperatively. The USC of the partial sternotomy minimizes the incision wound size and reduces postoperative pain. Conclusion: Our experiences indicate this mrnisternotomy approach as a very suitable and safe alternative to elective AVR with both mechanical as well as stemless protheses.
77